// Copyright 2015 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef NET_SSL_THREADED_SSL_PRIVATE_KEY_H_
#define NET_SSL_THREADED_SSL_PRIVATE_KEY_H_

#include <stddef.h>
#include <stdint.h>

#include <memory>
#include <vector>

#include "base/macros.h"
#include "base/memory/ref_counted.h"
#include "base/memory/weak_ptr.h"
#include "base/strings/string_piece.h"
#include "net/ssl/ssl_private_key.h"

namespace base {
class TaskRunner;
}

namespace net {

// An SSLPrivateKey implementation which offloads key operations to a background
// task runner.
class ThreadedSSLPrivateKey : public SSLPrivateKey {
public:
    // Interface for consumers to implement to perform the actual signing
    // operation.
    class Delegate {
    public:
        Delegate() { }
        virtual ~Delegate() { }

        // These methods behave as those of the same name on SSLPrivateKey. They
        // must be callable on any thread.
        virtual Type GetType() = 0;
        virtual std::vector<SSLPrivateKey::Hash> GetDigestPreferences() = 0;
        virtual size_t GetMaxSignatureLengthInBytes() = 0;

        // Signs |input| as a digest of type |hash|. On success it returns OK and
        // sets |signature| to the resulting signature. Otherwise it returns a net
        // error code. It will only be called on the task runner passed to the
        // owning ThreadedSSLPrivateKey.
        virtual Error SignDigest(Hash hash,
            const base::StringPiece& input,
            std::vector<uint8_t>* signature)
            = 0;

    private:
        DISALLOW_COPY_AND_ASSIGN(Delegate);
    };

    ThreadedSSLPrivateKey(std::unique_ptr<Delegate> delegate,
        scoped_refptr<base::TaskRunner> task_runner);

    // SSLPrivateKey implementation.
    Type GetType() override;
    std::vector<SSLPrivateKey::Hash> GetDigestPreferences() override;
    size_t GetMaxSignatureLengthInBytes() override;
    void SignDigest(Hash hash,
        const base::StringPiece& input,
        const SignCallback& callback) override;

private:
    ~ThreadedSSLPrivateKey() override;
    class Core;

    scoped_refptr<Core> core_;
    scoped_refptr<base::TaskRunner> task_runner_;
    base::WeakPtrFactory<ThreadedSSLPrivateKey> weak_factory_;

    DISALLOW_COPY_AND_ASSIGN(ThreadedSSLPrivateKey);
};

} // namespace net

#endif // NET_SSL_THREADED_SSL_PRIVATE_KEY_H_
